Don't check lines beginning with '#', since they could contain a path with the unexpected word in them.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173306 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Lexer/unknown-char.c b/test/Lexer/unknown-char.c
index 334df37..57f7904 100644
--- a/test/Lexer/unknown-char.c
+++ b/test/Lexer/unknown-char.c
@@ -1,2 +1,2 @@
-// RUN: %clang_cc1 -E %s 2>&1 | not grep error
+// RUN: %clang_cc1 -E %s 2>&1 | grep -v '^#' | not grep error
  ` ` ` `